Why do people share fake news, even when they understand it is fake? Sharing, especially in social media, is (also) the result of social processes (e.g., social influence, social norms), whose role in affecting what users chose to share online, or what opinion to express is still not clear. Here at LABSS we are interested in understanding the social mechanisms that drive people's decisions online, both in terms of what facilitates fake news sharing and what limits the adoption of corrective behaviours.

Social psychology has long shown how beliefs and actions of individuals are affected by what they perceive the majority of their peers thinks or does. However, such perception may not always be correct and still guide individual behaviour. Specific features of social media can contribute to alter it. For example, perceptual social biases can lead to over-estimate the share of the community holding certain views, enhancing the likelihood that opinion misperceptions and misperceived social norms arise. Such a collective misunderstanding may lead unpopular views or undesirable behaviors like fake news sharing to be perceived as more socially approved than what they really are, and possibly decrease the perceived social support for actions aimed at correcting misbehavers.

By combining the observation of social platform data with online experiments and social simulation modeling we aim at better understanding the socio-cognitive dynamics behind misperceptions and hopefully provide useful insights on how to mitigate fake news spreading in online systems.